+ All Categories
Home > Documents > TECHNICAL SPECIFICATION FOR EPOXY SOLID-CAST/CAST …

TECHNICAL SPECIFICATION FOR EPOXY SOLID-CAST/CAST …

Date post: 16-Oct-2021
Category:
Upload: others
View: 15 times
Download: 0 times
Share this document with a friend
34
المتجددةلطاقةء والكهربا وزارة اMinistry Of Electricity and Renewable Energy لقابضة لكهرباء مصر الشركة اEgyptian Electricity Holding Company EDMS 08- 201- 2 EEHC DISTRIBUTION MATERIALS SPECIFICATION Date: 09-02-2021 0 TECHNICAL SPECIFICATION FOR EPOXY SOLID-CAST/CAST RESIN COIL DRY - TYPE DISTRIBUTION TRANSFORMERS 22/0.4 KV 50 KVA up to 5000 KVA (WITH / WITHOUT) ENCLOUSER
Transcript
Page 1: TECHNICAL SPECIFICATION FOR EPOXY SOLID-CAST/CAST …

Ministry Of Electricity and Renewable Energy وزارة الكهرباء والطاقة المتجددة

Egyptian Electricity Holding Company الشركة القابضة لكهرباء مصر

EDMS 08- 201- 2 EEHC DISTRIBUTION MATERIALS SPECIFICATION

Date: 09-02-2021

0

TECHNICAL SPECIFICATION

FOR EPOXY SOLID-CAST/CAST RESIN COIL

DRY - TYPE DISTRIBUTION TRANSFORMERS

22/0.4 KV

50 KVA up to 5000 KVA

(WITH / WITHOUT) ENCLOUSER

Page 2: TECHNICAL SPECIFICATION FOR EPOXY SOLID-CAST/CAST …

Ministry Of Electricity and Renewable Energy وزارة الكهرباء والطاقة المتجددة

Egyptian Electricity Holding Company الشركة القابضة لكهرباء مصر

EDMS 08- 201- 2 EEHC DISTRIBUTION MATERIALS SPECIFICATION

Date: 09-02-2021

1

EDMS 08-201-2

TECHNICAL SPECIFICATION

FOR EPOXY SOLID-CAST/CAST RESIN COIL

DRY - TYPE DISTRIBUTION TRANSFORMERS

22 / 0.4 KV

50 KVA up to 5000 KVA

(WITH / WITHOUT) ENCLOUSER

Issue: Feb. 2021 / Rev- 2

يتى بدء انعًم بانًواصفة فى 0202/9/2

اختياريةد بنود و وجفي حالOption items تحديدها بواسطة شركة التوزيع قبل الطرح. يجب

Page 3: TECHNICAL SPECIFICATION FOR EPOXY SOLID-CAST/CAST …

Ministry Of Electricity and Renewable Energy وزارة الكهرباء والطاقة المتجددة

Egyptian Electricity Holding Company الشركة القابضة لكهرباء مصر

EDMS 08- 201- 2 EEHC DISTRIBUTION MATERIALS SPECIFICATION

Date: 09-02-2021

2

CONTENTS

1. Scope ………………………………………………………………………………….. 4

2. Applicable standards ………………………………………………………….………. 4

3. Environmental conditions …………………………………………………………….. 4

4. Design and construction ………………………………………………......….……….. 5

4.1 Rated power …………………………………………………………….…………... 5

4.2 Overloads ………………………………………………………………….………... 5

4.3 Operation at higher than rated voltage ………………………………………………. 5

4.4 Windings (primary and secondary coils) …………………………............................. 5

4.5 Encapsulation ………………………………………………………...…………….... 6

4.6 Core ………………………………………………………………………………….. 6

5. Technical specification ………………………………………………………….…….. 8

6. Penalty and Rejection …………………………………………………………………. 9

6.1 Rejection of Materials…………………………………………………………….…. 9

6.2 Penalty and Rejection for Decreased Efficiency …………………………………… 9

6.3 Replacement of rejected Materials and Equipment ………..……………………… 10

7. Taps ……………………………………………………………………………...……10

8. Tape changer …………………………………………………...…………………….10

9. Core and coil assembly ……………………………………...………………………...12

10. Busbar connection ………………………………………….……..…………..……….12

11. Enclosure (If required) …………………………………...…………………………....13

12. Base ……………………………………………………...…………………………….14

13. Inspection and testing ……………………………………………………………..…...15

14. Type tests ………………………………………………………………………….…...15

15. Routine tests ……………………………………………………………………….......15

16. Special tests ………………………………………………………………………..…..16

17. Accessories ………………………………………………………………………….....16

17.1 Thermo-resistances on lv windings and/or core ……………...…………………….17

17.2 Anti-vibrating pads (optional).…………………………………………...................19

17.3 Ethernet communication channels (optional).……………………………………....19

17.4 Ventilation system (set of electric fans for air forced cooling (AF))..……………...20

17.5 Junction box for the PT100 sensor (optional)……………………………………....21

17.6 Data cables…………………………………………………………………….........21

Page 4: TECHNICAL SPECIFICATION FOR EPOXY SOLID-CAST/CAST …

Ministry Of Electricity and Renewable Energy وزارة الكهرباء والطاقة المتجددة

Egyptian Electricity Holding Company الشركة القابضة لكهرباء مصر

EDMS 08- 201- 2 EEHC DISTRIBUTION MATERIALS SPECIFICATION

Date: 09-02-2021

3

17.7 Protection for temperature controller & fans protection (optional)...........................22

18. Name plate …………………………………………………………………………......23

19. Instruction manuals ………………………………………………………………….....23

20. Drawings …………………………………………………………………………….....24

21. Spare parts………………………………………………………………………….......24

22. Warranty………………………………………………………………………………..25

TABLES

TABLE (1) …………………………………………………………………..…………...25

TABLE (2) …………………………………………………………………..…………...26

GUARANTEE TABLE ……………………………………………………………………27

Page 5: TECHNICAL SPECIFICATION FOR EPOXY SOLID-CAST/CAST …

Ministry Of Electricity and Renewable Energy وزارة الكهرباء والطاقة المتجددة

Egyptian Electricity Holding Company الشركة القابضة لكهرباء مصر

EDMS 08- 201- 2 EEHC DISTRIBUTION MATERIALS SPECIFICATION

Date: 09-02-2021

4

1 Scope

This specification covers the minimum technical requirements for design, engineering,

manufacturing, packing, installation, and testing of an epoxy solid-cast resin coil

(22/0.4KV) dry-type transformers (indoor installation) with enough detail to ensure that

true solid-cast coil transformers will be offered.

2 Applicable standards

Unless otherwise specified in this specification, the epoxy cast resin coil dry - type

transformers should comply with the latest edition of IEC standard and ISO codes of

standards as following:

IEC 60076 for power transformer

Part 1 General

Part 2 Temperature rise

Part 3 Insulation levels and dielectric tests

Part 4 Lightning impulse and switching impulse testing

Part 5 Ability to withstand short circuit

Part 11 Dry type power transformers

Part 12 Loading guide for dry type power transformers

Part 10 Determination of transformer and reactor sound levels

Part 20 Energy Efficiency

IEC 60214 for Tap-changers

Part 1 Performance requirements and test methods

ISO 9001 International standard for a quality management system (QMS)

3 Environmental conditions

Maximum relative Humidity : 95 %

Maximum altitude : 1000 m

Page 6: TECHNICAL SPECIFICATION FOR EPOXY SOLID-CAST/CAST …

Ministry Of Electricity and Renewable Energy وزارة الكهرباء والطاقة المتجددة

Egyptian Electricity Holding Company الشركة القابضة لكهرباء مصر

EDMS 08- 201- 2 EEHC DISTRIBUTION MATERIALS SPECIFICATION

Date: 09-02-2021

5

Ambient temperature : -5°C to +45°C (50°C as option)

35°C monthly average of the hottest month.

25°C yearly average

Where the monthly and yearly averages are as defined in 3.12 of IEC 60076-1

4 Design and construction

4.1 Rated power

The transformer should be designed so it can deliver continuously its rated current under

steady loading conditions without exceeding the temperature rise, if the applied voltage is

equal to the rated voltage and the supply is equal to its rated frequency.

4.2 Operation at higher than rated voltage

The transformer should be capable of service without damage under conditions where the

ratio of voltage over frequency exceeds the corresponding ratio at rated voltage and rated

frequency by no more than 5%.

4.3 Overloads

Dry type AF transformers should be overloaded according to IEC 60067-12 and for

transformer with thermal class (F) as illustrate in the table (1).

4.4 Windings (primary and secondary coils)

The high and low voltage coils should be wound with high conductivity aluminum

conductors (Copper is optional as per …. EDC requirements) and then Solid-cast

(Encapsulated under Vacuum and pressure) separately in molds.

Coils should be separated by uniform air space that permits free circulation of cooling air

between the coils.

Page 7: TECHNICAL SPECIFICATION FOR EPOXY SOLID-CAST/CAST …

Ministry Of Electricity and Renewable Energy وزارة الكهرباء والطاقة المتجددة

Egyptian Electricity Holding Company الشركة القابضة لكهرباء مصر

EDMS 08- 201- 2 EEHC DISTRIBUTION MATERIALS SPECIFICATION

Date: 09-02-2021

6

Windings should be properly sized, insulated and supported for the line and load voltages

and currents to be encountered in operation including short circuits, when the transformer is

properly installed using (class F), (class H is optional as per …. EDC requirements), rated

insulated material and adequately protected.

Construction of the transformer should separate the primary connections and the secondary

connections by placing them on opposite sides of the core.

The transformer core limb should be grounded to the base through a copper strap, and taps

should be provided on the primary.

4.5 Encapsulation (for high and low voltage coils)

The Encapsulation process should involve pre-heating the coils and then filling each mold

with degassed and thoroughly mixed epoxy under vacuum. Once filled, the coils should then

be oven cured to insure a solid void free casting. The oven curing process should be

controlled and monitored to ensure that each coil is properly cured. The high voltage coils

should withstand the half and full wave impulse tests as well as partial discharge tests to

insure a properly cured and void–free casting.

The epoxy should contain filler material providing characteristics superior to unfilled epoxy

including higher temperature rating, better heat conductivity, better arc resistance and

adhesion to the conductor, plus a coefficient of expansion closer to that of the conductor

material.

4.6 Core

The core should be constructed of the best quality, low loss; high permeability cold rolled

grain-oriented steel laminations, on-aging silicon steel insulated on both sides.

Page 8: TECHNICAL SPECIFICATION FOR EPOXY SOLID-CAST/CAST …

Ministry Of Electricity and Renewable Energy وزارة الكهرباء والطاقة المتجددة

Egyptian Electricity Holding Company الشركة القابضة لكهرباء مصر

EDMS 08- 201- 2 EEHC DISTRIBUTION MATERIALS SPECIFICATION

Date: 09-02-2021

7

It should be miter-corner-cut without burs and hand stacked into a cruciform arrangement of

different width of laminations, to provide a cross-section most nearly assembling the circular

cross-section inside the low voltage coil.

Laminations should be cut and stacked utilizing step-lap construction to reduce losses and

sound.

Designed flux density should be kept well below saturation (≤ 1.6 Tesla).

The assembled core should be braced with heavy structural steel angle or channel to apply

uniform clamping forces across the entire width, top and bottom.

The core should have steel straps running top to bottom down the front and back of each

core leg, inside the coils.

Horizontal and vertical bracing should be through bolted to insure consistent clamping

forces on all parts of the magnetic steel laminations.

The core should be protected from corrosion with a higher temperature rated rust-resistant

coating.

The temperature of the core, metallic parts and adjacent materials should not reach a value

that will cause damage to any part of the transformer.

The core assembly should enable the removal of the coils in the field, if this should become

necessary.

The entire core assembly should be covered with a resin-based lacquer for corrosion

protection before the coils are mounted.

Page 9: TECHNICAL SPECIFICATION FOR EPOXY SOLID-CAST/CAST …

Ministry Of Electricity and Renewable Energy وزارة الكهرباء والطاقة المتجددة

Egyptian Electricity Holding Company الشركة القابضة لكهرباء مصر

EDMS 08- 201- 2 EEHC DISTRIBUTION MATERIALS SPECIFICATION

Date: 09-02-2021

8

5 Technical specification

Transformer KVA Rating As described in table (2)

(1p.u for AN / 1.4 p.u for AF)

Cooling Class AN / AF

Type Ventilated dry type

Phases 3

Frequency 50 Hz

Taps Off Load +2×2.5%, -4X2.5%, On load (*)

Average winding temperature rise above

ambient temperature at rated current “C” (95@45 ambient &90 @50 ambient)/120

(*)

Insulation system temperature (class F) / (class H) (*)

Ambient temperature 45°C, 50°C (*)

Primary Voltage 22 KV

Primary Connection Delta

Secondary Voltage (at full load) 0.4 KV

Secondary connection Star

Vector Group Dyn11

Primary rated lightning impulse withstand

voltage (KVpeak) 125 KV

Insulation level: Rated short duration

separate source AC withstand voltage

(KVrms)

50 /5 KV

Duration of short circuit: Thermal (rms) 2 sec.

Dynamic (peak) (0.5sec (Cat 1), 0.25sec (Cat 2 and 3)) ±10%

S.C. level of 22 kV network 500 MVA

Impedance voltage at (75°C) at main tap As described in table (2)

Noise level As described in table (2)

Partial discharge ≤ 10 pc

Climate class C1

Environmental class E2

Fire protection F1

(*) Optional and as per ----EDC requirement.

Page 10: TECHNICAL SPECIFICATION FOR EPOXY SOLID-CAST/CAST …

Ministry Of Electricity and Renewable Energy وزارة الكهرباء والطاقة المتجددة

Egyptian Electricity Holding Company الشركة القابضة لكهرباء مصر

EDMS 08- 201- 2 EEHC DISTRIBUTION MATERIALS SPECIFICATION

Date: 09-02-2021

9

6 Penalty and rejection

6-1 Rejection of Material:

If during inspection tests at the works attended by the customer representative engineer

any material is found to be defective or not manufactured according to the specifications

agreed upon the customer representative engineer have the right to reject such material if

he is not convinced that it can satisfactorily be repaired. In such case the contractor

should be obliged to replace the defective material without being entitled to any extra

payment whatsoever or to any extension of time of completion of contract.

6-2 Penalty and Rejection for Decreased Efficiency

The contractor should keep the No load losses and load losses and to be within the

guaranteed values, should the loss values, measured from the works tests, exceed the

allowable tolerances in the IEC or approved equal standards, then the customer

representative should have the right to reject the transformer with such losses.

However, the measured losses deviate from the guaranteed figures, but lie within the

allowable tolerances (10% total losses or 15% individual losses), then the excess losses

should be evaluated as per the following formula and the contractor should be penalized

accordingly.

P. W = K x 8760 x C [dwi+ (LS.F) (P2) dwcu] LE

Where,

K = Present worth factor (L.E)

K = ((1+i)N -1) / i (i+1)

N )

i: latest interest rate from Central Bank of Egypt.

N: number of years. (20 years)

Page 11: TECHNICAL SPECIFICATION FOR EPOXY SOLID-CAST/CAST …

Ministry Of Electricity and Renewable Energy وزارة الكهرباء والطاقة المتجددة

Egyptian Electricity Holding Company الشركة القابضة لكهرباء مصر

EDMS 08- 201- 2 EEHC DISTRIBUTION MATERIALS SPECIFICATION

Date: 09-02-2021

10

C = Cost of KWH. (According to the max commercial cost of KWH and can be adjusted

as EEHC update)

LS.F = Loss factor for the load = 0.4.

Wi = Iron losses in KW at rated voltage and main tapping

Wload = Load losses in KW at full load and 75ºC.

P = Peak load (P.U.) = 0.8.

No credit should be given for any decrease in the value of loss(es) below the guaranteed.

6-3 Replacement of Rejected Material and Equipment

If according to the above articles, any material or equipment is rejected, the contractor

should be obliged to replace it without extra payment.

7 Taps

The taps are rigidly supported by cast into the epoxy along the central face of each high

voltage coil; taps are changed by moving the flexible bolted links from one connecting point

to the other, and tap terminals are clearly numbered and referenced on the transformer name

plate.

8 Tap Changer

Normal ratio of transformation of voltages between phases on the primary and secondary

windings of the transformer should be 22 kV/0.4 kV.

7 positions Tap Changer and the associated operating mechanism should be able to vary the

ratio of transformation in steps of 2.5%.

The tap changer enclosure should be equipped with a suitable transparent window of

thickness not less than 3 mm to grant observation of the current tapping.

The range of transformation ratio should be +5% to -10%.

Page 12: TECHNICAL SPECIFICATION FOR EPOXY SOLID-CAST/CAST …

Ministry Of Electricity and Renewable Energy وزارة الكهرباء والطاقة المتجددة

Egyptian Electricity Holding Company الشركة القابضة لكهرباء مصر

EDMS 08- 201- 2 EEHC DISTRIBUTION MATERIALS SPECIFICATION

Date: 09-02-2021

11

Voltage trapping should be provided on the high voltage side of the transformer.

Direction of operation for Raise/Lower tap should be provided.

On Load Tap Changer (Option As … EDC Requirements)

Tap changer operating mechanism motor should be 3 phase, 400V & 50Hz and all auxiliary

supply voltage should be DC 110V.

The voltage sensing equipment should prevent operation of the tap-changer if the reference

voltage is lost.

The relays, switches and push buttons should be enclosed in a weatherproof cubicle and be

readily accessible for maintenance at ground level with the transformer energized.

The Motor Drive Unit of the OLTC should contain a thermostatically controlled anti-

condensation heater, a door operated light and a manual handle for emergency and

maintenance operation.

It should be weatherproof and dust proof (IP54) and should be bolted to the transformer

main tank in a convenient position such that the operator standing at ground level can carry

out maintenance on all equipment contained in the cabinet with the transformer energized.

Tap changer mechanism should send signal to initiate Indication/Alarm for the following:

1) Tap changer in progress

2) Tap changer incomplete

3) Out of step Indication

4) Supply voltage failure

5) Tap position

6) Tap changer counter

Page 13: TECHNICAL SPECIFICATION FOR EPOXY SOLID-CAST/CAST …

Ministry Of Electricity and Renewable Energy وزارة الكهرباء والطاقة المتجددة

Egyptian Electricity Holding Company الشركة القابضة لكهرباء مصر

EDMS 08- 201- 2 EEHC DISTRIBUTION MATERIALS SPECIFICATION

Date: 09-02-2021

12

9 Core and coil assembly

Construction should consist of separate high and low voltage coil for each phase, mounted

coaxially with high/low air space between coils adequate for the rated voltage potentials.

Coils should be mounted concentrically and supported in place on the transformer core to

restrain movement in shipping and in services.

Each coil should be supported on epoxy or equivalent fiber glass blocks withstand

mechanical and thermal strength, top and bottom, with resilient pads to retain the coils

while permitting thermal expansion under loading.

The core and coil assembly should be designed and manufactured to withstand without

damage the short circuit testing as defined in IEC standards.

10 Busbar connection

All bus work should be designed to withstand maximum short circuit stresses when

connected to a supply system having a fault capacity of 20 KA for 3 sec., symmetrical at

rated voltage, and to meet all test voltage requirements, without audible or visible corona.

Busbar should be sized to maintain a current density of less than or equal 1.5 amps per

mm2 at 100% name plate load and provided with connector plates bimetal AL/CU.

I. Low voltage busbars connection should be high conductivity material, Connections of

coil windings to busbar should be brazed or welded using shielded arc techniques or

friction welding technique designed to provide high joint integrity. Connection and

terminal bolting surfaces should be tin or silver-plated (for copper bars). Bolted

connections should include spring washers to maintain bolted surface pressure. All

busbars should be sized to conform to industry standards and practices, for the amperes

involved and maximum specified ambient temperatures.

Page 14: TECHNICAL SPECIFICATION FOR EPOXY SOLID-CAST/CAST …

Ministry Of Electricity and Renewable Energy وزارة الكهرباء والطاقة المتجددة

Egyptian Electricity Holding Company الشركة القابضة لكهرباء مصر

EDMS 08- 201- 2 EEHC DISTRIBUTION MATERIALS SPECIFICATION

Date: 09-02-2021

13

II. High voltage busbar should be high conductivity material, and fixed with three epoxy

resin HV insulators with 2 cm/kV min. Leakage path with bolt-connected joint and

terminal surfaces tin or silver plated.

III. High voltage leads delta connection should be copper busbar/rod/tube insulated with

technically accepted types of terminations. The tap’s lead should be flexible cable or

solid links or jumpers.

IV. Ground busbar should be copper with 150 mm2 C.S.A, extending the full length of two

opposite sides of the enclosure. It should have provisions to mount appropriate terminal

connection for adjacent switchgear or external grounding.

V. A galvanized shielded copper ground should be applied to facilitate the grounding of

each metal part with the following specs:

Copper: 99.99 % purity minimum.

Width and Thickness: 3 cm *1.5 mm at least. (effective C.S.A at least 35 mm2)

Flexibility: full.

Number of Shielded conductors to ground the transformer body: 2

11 Enclosure (If required)

Enclosure's dimensions should be suitable for installation in transformer's room with IP23.

Transformer with IP00 should be mounted in steel kiosk with IP23 to knockdown enclosure

with anti-corrosion treatment (electrostatic painting).

Enclosure should have a removable front face to gain access to the high voltage connection

equipment with two easy handles.

Page 15: TECHNICAL SPECIFICATION FOR EPOXY SOLID-CAST/CAST …

Ministry Of Electricity and Renewable Energy وزارة الكهرباء والطاقة المتجددة

Egyptian Electricity Holding Company الشركة القابضة لكهرباء مصر

EDMS 08- 201- 2 EEHC DISTRIBUTION MATERIALS SPECIFICATION

Date: 09-02-2021

14

Entrance Cables: from up or/and down of the enclosure by reinforced aluminum material of

thickness not less than 3 mm.

Enclosure thickness for all sides, cover and bottom should be not less than 2.5 mm before

electrostatic painting.

Enclosures should be suitable for complete transformer lifting with Eye Hooks or Lifting

Eyes.

The factories should make the design and beams to approve that the total weight of the unit

can be lifted from enclosure without removing the whole ceiling of it.

The enclosure should be equipped with (3) suitable transparent windows of thickness not

less than 3 mm (one for each phase), and should be against L.V. side of the transformer.

(door is accepted with maintained IP 23).

The enclosure should be provided with two adequate fans to ensure uniform heat transfer

(option as per ... EDC requirements)

12 Base

The transformer base should be a separate rigid steel weldment capable of supporting the

core-and-coil assembly with enclosure.

Construction should include provisions for lifting as well as for jacking and skidding or

rolling in both directions.

Two stainless steel ground pads (nuts) with two tapped holes for attaching ground leads

should be provided, one in each diagonally opposite corner of the base.

Lifting provisions should be designed for lifting the transformer and the core-and-coil

assembly, separately or together.

Page 16: TECHNICAL SPECIFICATION FOR EPOXY SOLID-CAST/CAST …

Ministry Of Electricity and Renewable Energy وزارة الكهرباء والطاقة المتجددة

Egyptian Electricity Holding Company الشركة القابضة لكهرباء مصر

EDMS 08- 201- 2 EEHC DISTRIBUTION MATERIALS SPECIFICATION

Date: 09-02-2021

15

13 Inspection and testing

Tests should be according to latest applicable IEC standards. A complete set of certified

type and special test reports covering specified complete tests should be provided.

…. EDC reserves its right to witness tests.

Test values not specified by standards should be subject to the agreement between the

manufacturers and the purchaser.

14 Type tests

The type tests should be made on one transformer of each type in accordance with the

requirements of IEC standards for Dry-Type distribution transformers.

There are including and not limited to the following:

1. Lightning impulse test.

2. Temperature- rise test.

15 Routine tests

The routine tests should be applied on each transformer in accordance with the

requirements of IEC 60076-11 standards for dry type transformer.

There are including and not limited to the following:

1. Winding resistance test.

2. Turns ratio test and vector group.

3. Impedance voltage and load-loss test.

4. No load loss and no-load current test.

5. Applied voltage dielectric test.

6. Induced A.C withstand voltage test.

7. Partial discharge measurement (the value should be less than 10 pc).

Page 17: TECHNICAL SPECIFICATION FOR EPOXY SOLID-CAST/CAST …

Ministry Of Electricity and Renewable Energy وزارة الكهرباء والطاقة المتجددة

Egyptian Electricity Holding Company الشركة القابضة لكهرباء مصر

EDMS 08- 201- 2 EEHC DISTRIBUTION MATERIALS SPECIFICATION

Date: 09-02-2021

16

يحق لممثلي شركات التىزيع بحد أدنى اثنين معاينة مراحل تصنيع المحىل ويحق للجنة الرفض في حال وجىد

اختلاف عن المىاصفة الفنية المعتمدة والتي تم الطرح بها.

16 Special tests

The special tests should be according to IEC standards for dry type transformers when

required. There are including and not limited to the following:

1. Measurement of sound level test

2. Short circuit test.

3. Environment test.

4. Climatic test.

5. Fire behavior test.

17 Accessories

عتًاد انصادر نهًحول بانًشتًلاتويكتفى بالإينفصهة عتًاد يهحقات انًحول إلا يهزو.

An instantaneous and maximum temperature – indicating thermometer should be provided

on the front of transformer.

The transformer and their accessories should be able to withstand the effect of the rated

short circuit through windings for 2 seconds duration.

The transformer and their accessories should be able to withstand the effect of the dynamic

short circuit current through the windings for (0.5sec (Cat 1), 0.25sec (Cat 2 and 3)) ±10%.

The transformer should have a weatherproof name plate of stainless-steel material placed

in a clear position.

Page 18: TECHNICAL SPECIFICATION FOR EPOXY SOLID-CAST/CAST …

Ministry Of Electricity and Renewable Energy وزارة الكهرباء والطاقة المتجددة

Egyptian Electricity Holding Company الشركة القابضة لكهرباء مصر

EDMS 08- 201- 2 EEHC DISTRIBUTION MATERIALS SPECIFICATION

Date: 09-02-2021

17

17.1 Thermo-resistances on LV windings and/or core

Transformer should be provided with 6 fans to give a forced air-cooled rating above the

self-cooled full rating, miniature circuit breaker and control wiring (wire markers

included).

A thermo-resistance PT100 (Platinum "100" for the resistance in ohms at 0 oC) should be

connected to a suitable electronic device.

PT100 thermo-resistance should allow logging of windings and core and a remote

transmission of data.

A thermal sensor and a fan controller should be supplied, installed inside the enclosure.

The temperature controller should log the signal coming from three (3) PT100s at least and

indicates the measured temperature.

It should include 2 relays with adjustable threshold for the alarm and release signals as well

as an auxiliary contact to control a possible set of fans for air forced ventilation.

It should be a microcontroller/microprocessor-based unit specifically designed for dry type

and cast resin transformers.

It should be developed with layout and advantages of the following technology platform:

1. Dual display.

2. Voting function.

3. The controller with increased operational capacity.

4. Data management.

5. HFN (Hourly Fan No cycling)

It should provide in a single product the following outputs:

1. Analog 4-20 mA

2. Digital RS485 Modbus RTU.

Page 19: TECHNICAL SPECIFICATION FOR EPOXY SOLID-CAST/CAST …

Ministry Of Electricity and Renewable Energy وزارة الكهرباء والطاقة المتجددة

Egyptian Electricity Holding Company الشركة القابضة لكهرباء مصر

EDMS 08- 201- 2 EEHC DISTRIBUTION MATERIALS SPECIFICATION

Date: 09-02-2021

18

It should be able to monitor the temperature of the transformer by a remote communication

system.

It should in addition to transmitting real-time temperatures, offer the possibility to vary all

the settings including the relays intervention thresholds.

It should be equipped with three (3) PT100 inputs (at least) to monitor the temperature of

the core and windings while sensor inputs should be available.

It should have the following:

1. ALARM relays to give a signal for high temperatures.

2. TRIP relay to give signal to disconnect the transformer in case it reaches the

maximum threshold through C.B, RMU, ... etc.

3. FANS relays to start the ventilation system.

4. FAULT relay to indicate the damage or break of PT100 sensors and the

critical failures (trip operation failed).

5. SIGNAL relay for fans failure at BMS (Building Management System)

It should be supplied with a coating on the electronic cards, resistant to difficult weather

conditions, particularly characterized by high temperature and humidity.

It should be universal power supply with input from 24 to 240 Vac/dc.

"the fan controller box must be tightly closed to protect it from dust and impurities" such

that the screen and the selector can be accessed from outside without need to open the

enclosure.

The thermal sensor and a fan controller should be used to indicate winding temperature and

provide a single-phase voltage to operate fans or to disconnect fans according to the

temperature of winding and auxiliary contacts to provide alarm and to trip the M.V.C.B.

Page 20: TECHNICAL SPECIFICATION FOR EPOXY SOLID-CAST/CAST …

Ministry Of Electricity and Renewable Energy وزارة الكهرباء والطاقة المتجددة

Egyptian Electricity Holding Company الشركة القابضة لكهرباء مصر

EDMS 08- 201- 2 EEHC DISTRIBUTION MATERIALS SPECIFICATION

Date: 09-02-2021

19

All control wiring and thermal sensor must be in ducts and thermal flexible plastic pipes.

The manufacturer must provide a brief user manual (monitoring steps) for the fan-

controller and to be installed beside it.

The transformer should be provided with indicating lamps on the transformer outer surface

with a lamp for each fan to indicate whether the fans are working properly or not, with an

arrangement of the lamps indicating their dependency for each fan.

17.2 Anti-vibrating pads

Anti-vibrating pads should be composed of special rubber supports supplied loose to be

positioned by the … EDC under the transformer's wheels. (Noise Reduction Dumper)

They should allow a great reduction of the vibrations transmitted to the structure and

therefore of the noise and possibility of structural resonances.

Anti-vibrating supports should be designed and supplied for special application in

compliance with …EDC specification.

17.3 Ethernet communication channels (Optional)

The Ethernet communication channel should be a microcontroller/microprocessor-based

device.

The Ethernet communication channel should be designed for dry type cast resin

transformers with integrated Ethernet port.

The Ethernet communication channel should be equipped with all the necessary functions

needed to monitor and control the temperature of the transformer.

The Ethernet communication with the network should be via Modbus TCP/IP protocol

allowing to display and to program all the unit functions from the comfort of the desk.

Page 21: TECHNICAL SPECIFICATION FOR EPOXY SOLID-CAST/CAST …

Ministry Of Electricity and Renewable Energy وزارة الكهرباء والطاقة المتجددة

Egyptian Electricity Holding Company الشركة القابضة لكهرباء مصر

EDMS 08- 201- 2 EEHC DISTRIBUTION MATERIALS SPECIFICATION

Date: 09-02-2021

20

The Ethernet communication channel should maintain the traditional PT100 inputs and

relays for ALARM, FAULT, TRIP, and FANs.

The unit should be supplied with a coating on the electronic cards, resistant to difficult

weather conditions, particularly characterized by high temperature and humidity.

The protection relays should be universal power supply with input from 24 to 240Vac/Vdc.

17.4 Ventilation system (set of electric fans for air forced cooling (AF))

Ventilation system should include 2 sets ionized aluminum bar cooling fans each bar

consists of 3 fans, based on transformer type and power, fixed to the base of the

transformer.

For a proper performance, each set of fans should be assembled together with a control and

command switchboard.

The cooling fans should provide optimal solutions for air forced cooling of dry

transformers and the on-board ventilation system should allow the transformer to maintain

an optimal temperature, increasing its safety even in case of momentary overload. The

structure of the fans should provide a fast and easy assembly/installation of the fans on the

transformer enclosure.

The cooling fans should have high performance crossflow and centrifugal to dissipate heat

generated by transformer losses while complying and assure fail-safe operations in all

zones.

The cooling fans should have the following specifications:

Operation : indoor

Degree of protection : IP ≥ 20

Speed : ≥ 1800 rpm

Page 22: TECHNICAL SPECIFICATION FOR EPOXY SOLID-CAST/CAST …

Ministry Of Electricity and Renewable Energy وزارة الكهرباء والطاقة المتجددة

Egyptian Electricity Holding Company الشركة القابضة لكهرباء مصر

EDMS 08- 201- 2 EEHC DISTRIBUTION MATERIALS SPECIFICATION

Date: 09-02-2021

21

Power : ≤ 250 watt (for each fan)

Noise : ≤ 71 dB

Installation : vertical / horizontal

Ambient temperature : -5 °C to 45 °C (50 °C as option)

Motor insulation class : B

17.5 Junction box for the PT100 sensor

The cast resin transformer should be equipped with a box designed and manufactured for

a quick, safe and economic connection of the sensors. The box should detect the

temperature of the cast resin transformers.

The length of the cables as well as the type of sensors should be determined according to

the … EDC specifications.

The box should come with 3 Pt100 sensors at least with not less than 2.5 m cable each.

The box should have the following specifications:

Material : Polyamide with cable gland features

Dimensions : 10:14 mm

Degree of protection : IP ≥ 54

Flame resistance : UL 94V0 Operating

Operating temperature : from -5°C to +45°C / +50°C (optional)

17.6 Data cables

The data cables should be for the transport of the data signals with all the protection

requirements: mod. CTES technical specifications of the extension cable for PT100.

The data cables should provide the following specifications:

Page 23: TECHNICAL SPECIFICATION FOR EPOXY SOLID-CAST/CAST …

Ministry Of Electricity and Renewable Energy وزارة الكهرباء والطاقة المتجددة

Egyptian Electricity Holding Company الشركة القابضة لكهرباء مصر

EDMS 08- 201- 2 EEHC DISTRIBUTION MATERIALS SPECIFICATION

Date: 09-02-2021

22

1 Cable 20 x AWG 20/19 Cu/Sn

2 Flame retardant insulation PVC105

3 CEI 20.35 IEC 332.1 regulations

4 Maximum operating temperature: 90°C

5 Conformation: 4 sets of three twisted and colored conductors

6 Shield in Cu/Sn

7 Flame retardant PVC sheath

17.7 Protection for temperature controller & fans protection

This device should provide additional protection to protection units. The device should

provide protection for the fans against over current and under voltage.

This device should provide overvoltage protection and should be used on systems where

there are large surges and fluctuations in 230 Vac power supply.

It should be used for cutting the peak voltage that is generated when the MV switch is

closed.

It should be easily installed inside the panel through the DIN EN50022 rail.

It should have a red led to indicate the possible intervention of fuses.

It should have the following specifications:

Power supply : 230 Vac.

Input voltage : 230 Vac +/-10% 50Hz

Delay time : settable from 1 to 5 sec

Housing material : Polyamide UL 94V2

Protection fuses : 2 & 5 Amps (delayed)

Ambient operating temperature : -5 °C to +45 °C (50 °C as option)

Page 24: TECHNICAL SPECIFICATION FOR EPOXY SOLID-CAST/CAST …

Ministry Of Electricity and Renewable Energy وزارة الكهرباء والطاقة المتجددة

Egyptian Electricity Holding Company الشركة القابضة لكهرباء مصر

EDMS 08- 201- 2 EEHC DISTRIBUTION MATERIALS SPECIFICATION

Date: 09-02-2021

23

18 Name plate

Transformer serial No. and rated power should be engraved on transformer body at LV

side. Each transformer should be fitted with a name plate of weather proof materials fitted

in a visible position, showing the information listed below. Entries on the plate should be

indelibly marked by etching or engraving:

Each transformer should have two Name Plats one on transformer body and second fix on

Enclosure) fixed by rivets:

1. Type of transformer 2. IEC codes 3. Manufacturer's name

4. Serial number 5. Year of manufacture 6. Insulation level

7. Number of phases 8. Rated power 9. Rated frequency

10. Rated voltage 11. Rated current 12. Vector group

13. Tap position 14. Impedance voltage (% Z) 15. Type of cooling

16. Total mass 17. Temperature rise of windings 18. Customer: … EDC

19. Short Circuit Duration 20. P.O NO. / Year

19 Instruction manuals

The bidder should be supply with shipment of the transformer complete installation,

operation and maintenance instruction/manuals suitable for the specific item(s) being

supplied, including information from the manufacturer of each purchased accessory.

Page 25: TECHNICAL SPECIFICATION FOR EPOXY SOLID-CAST/CAST …

Ministry Of Electricity and Renewable Energy وزارة الكهرباء والطاقة المتجددة

Egyptian Electricity Holding Company الشركة القابضة لكهرباء مصر

EDMS 08- 201- 2 EEHC DISTRIBUTION MATERIALS SPECIFICATION

Date: 09-02-2021

24

It should include interconnected diagrams, drawings and instructions describing procedures

for items that will be shipped to be assembled and interconnected for operation when

installed.

These should contain strict instructions as required for carrying, moving by skidding or

rolling, and lifting the transformer and accessories.

The manual should include the instructions for tap changing, enclosure assembly,

disassembly, temperature indicator reading, setting procedures and other information

designed to assist in proper operation and periodic maintenance of the equipment being

supplied.

Key interlocking should be identified, and serial number should be supplied.

All manuals, instructions and supporting drawings and parts lists supplied by the

manufacturer and supplemental instruction and data supplied by accessory manufacturers

should be in English, clearly readable and arranged in such format to make the subject

items easily identifiable.

20 Drawings

Bidder should supply a complete set of “as manufactured” drawings and wiring diagrams

including interconnection diagrams of all components and assemblies of the equipment

which assist in operation and maintenance of the equipment.

All drawings should be compatible with current industrial standards and good industrial

practice.

All information should be in English language, clearly readable, with IEC standard

symbols, device model, numbers and other requirements.

Page 26: TECHNICAL SPECIFICATION FOR EPOXY SOLID-CAST/CAST …

Ministry Of Electricity and Renewable Energy وزارة الكهرباء والطاقة المتجددة

Egyptian Electricity Holding Company الشركة القابضة لكهرباء مصر

EDMS 08- 201- 2 EEHC DISTRIBUTION MATERIALS SPECIFICATION

Date: 09-02-2021

25

All Dimensions should be in centimeters.

21 Spare parts (as option)

Tender should contain a list of recommended needed spare parts.

22 Warranty

The manufacturer should warrant the dry distribution transformer to be free from defects in

both material and industry for period of 12 months from the time of operation or 18 months

after delivers to ……EDC

In case of supplying for the first time, the warranty should be 4 years starting from delivery

date.

Table (1)

For AN cooling

Previous

continuous

loading

Windings

temperature/

hot spot

Duration (min.) of overloading for specific

levels of overloading (% of rated power),

Max. temperature for hot spot 145 oC

% of rated

power oC

10%

min.

20%

min.

30%

min.

40%

min.

50%

min.

50 46/54 50 45 30 25 20

75 79/95 35 25 17 13 10

90 103/124 15 8 6 5 3

100 120/145 4 2 0 0 0

Page 27: TECHNICAL SPECIFICATION FOR EPOXY SOLID-CAST/CAST …

Ministry Of Electricity and Renewable Energy وزارة الكهرباء والطاقة المتجددة

Egyptian Electricity Holding Company الشركة القابضة لكهرباء مصر

EDMS 08- 201- 2 EEHC DISTRIBUTION MATERIALS SPECIFICATION

Date: 09-02-2021

26

Table (2)

22 KV /0.4 KV

POWER

(KVA)

IRON LOSSES

(W)

LOAD LOSSES

(W)

at 75° C

Noise Level

dB

% Z at

75 oC

(±10%)

50 200 1200 45 4

63 252 1400 48 4

100 280 1700 50 4

160 400 2300 50 4

250 520 3300 53 4

315 655 4000 54 4

400 750 4800 55 4

500 930 5600 56 4

630 1100 6800 57 4

800 1300 8200 58 5

1000 1550 8900 59 5

1250 1800 11500 61 5

1500 2100 12800 61 6

1600 2200 14000 61 6

2000 2600 17500 62 6

2500 3100 20000 65 6

Page 28: TECHNICAL SPECIFICATION FOR EPOXY SOLID-CAST/CAST …

Ministry Of Electricity and Renewable Energy وزارة الكهرباء والطاقة المتجددة

Egyptian Electricity Holding Company الشركة القابضة لكهرباء مصر

EDMS 08- 201- 2 EEHC DISTRIBUTION MATERIALS SPECIFICATION

Date: 09-02-2021

27

GUARANTEE TABLE

DRY TRANSFORMER 22 KV / 0.4 KV

3150 3800 23000 65 7

5000 6000 31500 65 7

Page 29: TECHNICAL SPECIFICATION FOR EPOXY SOLID-CAST/CAST …

Ministry Of Electricity and Renewable Energy وزارة الكهرباء والطاقة المتجددة

Egyptian Electricity Holding Company الشركة القابضة لكهرباء مصر

EDMS 08- 201- 2 EEHC DISTRIBUTION MATERIALS SPECIFICATION

Date: 09-02-2021

28

- Manufacturer ........................

- Type of transformer …… .…………………

- Method of cooling …… ………………….

- Standard of specifications …… ………………….

- Vector group

- Winding Techniques:

Primary

Secondary

…… ………………….

………………………..

…… ………………….

…… ………………….

- Transformer ratio at main tapping and no load …… ……… / ……..KV

- Transformer ratio at main tapping and full load: …… ……… / ……..KV

- At unity P.F. …… ……… / ……..KV

- At 0.8 P.F. …… ……… / ……..KV

- Rated primary current at main tapping and full load …… ………………A

- Rated secondary current at main tapping and full load …… ………………A

- Current density in primary winding at full load …… ……………A /mm2

- Current density in secondary winding at full load …… ……………A /mm2

- Primary current at main tapping and no load …… ………………A

- Flux density in core and yoke at rated voltage at main tapping and …… ………………Tesla

Page 30: TECHNICAL SPECIFICATION FOR EPOXY SOLID-CAST/CAST …

Ministry Of Electricity and Renewable Energy وزارة الكهرباء والطاقة المتجددة

Egyptian Electricity Holding Company الشركة القابضة لكهرباء مصر

EDMS 08- 201- 2 EEHC DISTRIBUTION MATERIALS SPECIFICATION

Date: 09-02-2021

29

full load

- Rated output with self-air cooling ……………………KVA

- Rated output with forced air cooling ……………………KVA

- Permissible overload duration without change of specified temperature rise

10% overload starting from 50% rated output ………………Hr

20% overload starting from 75% rated output ………………Hr

30% overload starting from 90% rated output ……………....Hr

40% overload starting from 100% rated output ………………Hr

50% overload starting from 100% rated output ………………Hr

- Tap changer (On load / Off load) ….… / ..….

- Number of steps …………….

- Voltage corresponding to each step. ….………KV

- Insulation levels for line terminal

- Impulse withstand voltage + 1/50 microseconds wave (peak) ………………KV

- One-minute power frequency withstand voltage for primary and

secondary windings (RMS)

………………KV

- Max symmetrical short circuit stresses withstand at rated voltage ………………KA

- Induced voltage test for primary winding (RMS) ………………KV

Page 31: TECHNICAL SPECIFICATION FOR EPOXY SOLID-CAST/CAST …

Ministry Of Electricity and Renewable Energy وزارة الكهرباء والطاقة المتجددة

Egyptian Electricity Holding Company الشركة القابضة لكهرباء مصر

EDMS 08- 201- 2 EEHC DISTRIBUTION MATERIALS SPECIFICATION

Date: 09-02-2021

30

- Electrical performance and characteristic

- Resistance per phase at 75 °C

- Primary winding

- Secondary winding

………………Ohm

………………Ohm

- Impedance voltage at full load and main tapping 75 °C ...…………… Ohm

- Equivalent resistance referred to primary winding ………………Ohm

- Equivalent reactance referred to primary winding ………………Ohm

- Regulation at

- Unit PF and 4/4, 3/4, 1/2, 1/4 Full load

- 0.8 PF lagging 4/4, 3/4, 1/2, 1/4 Full load

…………………%

…………………%

- magnetizing primary current at main tapping …………………A

- Partial discharge …………………PC

- Losses and efficiency

- Load losses at full load and main tapping at unity PF and 75°C ………………KW

- Iron losses at rated voltage and main tapping ………………KW

- Total losses at full load and main tapping at unity PF and 75°C ………………KW

- Efficiency at

140% full load at 0.8 / unity PF …………………%

Page 32: TECHNICAL SPECIFICATION FOR EPOXY SOLID-CAST/CAST …

Ministry Of Electricity and Renewable Energy وزارة الكهرباء والطاقة المتجددة

Egyptian Electricity Holding Company الشركة القابضة لكهرباء مصر

EDMS 08- 201- 2 EEHC DISTRIBUTION MATERIALS SPECIFICATION

Date: 09-02-2021

31

125% full load at 0.8 / unity PF …………………%

100% full load at 0.8 / unity PF …………………%

75% full load at 0.8 / unity PF …………………%

50% full load at 0.8 / unity PF …………………%

25% full load at 0.8 / unity PF …………………%

Temperature rise

- Max temperature rise at 45°C ambient at full load of

Winding

Iron core

Hot spot

………………… °C

………………… °C

………………… °C

- Insulation class ..………………..

- Cooling system ..…………………

- Number of cooling units ..……………..…

- Number of air fans per cooling units fan diameter /rating / and

discharge No./mm/HP/1tr/min

..………………..…

- Material of core ..…………………

- Material of Enclosure .………………….

- Thickness of Enclosure

- Sides

………………...…mm

Page 33: TECHNICAL SPECIFICATION FOR EPOXY SOLID-CAST/CAST …

Ministry Of Electricity and Renewable Energy وزارة الكهرباء والطاقة المتجددة

Egyptian Electricity Holding Company الشركة القابضة لكهرباء مصر

EDMS 08- 201- 2 EEHC DISTRIBUTION MATERIALS SPECIFICATION

Date: 09-02-2021

32

- Cover

- Bottom

…………….…..…mm

………………..…mm

Insulation material

- Primary winding

- Secondary winding

- Major insulation

- Core plates

.………………

.………………

.………………

.………………

- Number and type of coils per phase:

- Primary windings (AL/CU)

- Secondary windings (AL/CU)

.………………

.………………

.………………

- Weight of core ……………….tons

- Weight of windings ……………….tons

- Weight of transformer ready for shipping …………..…..tons

- Dimension of transformer (without enclosure) (L× W× H) …………….…

- Dimension of enclosure (L× W× H) ………………

- The min. clearance from winding to enclosure .………………

- Protection degree (IP) for:

Cooling fans

……………….

Page 34: TECHNICAL SPECIFICATION FOR EPOXY SOLID-CAST/CAST …

Ministry Of Electricity and Renewable Energy وزارة الكهرباء والطاقة المتجددة

Egyptian Electricity Holding Company الشركة القابضة لكهرباء مصر

EDMS 08- 201- 2 EEHC DISTRIBUTION MATERIALS SPECIFICATION

Date: 09-02-2021

33

Enclosure

Junction box

……………….

……………….

- Noise level ……………….

- Climate class ……………….

- Environmental class ……………….

- Fire protection class ……………….

I / We guarantee the data given above for the equipment offered.

Signature: ………………………………

Date: …………..………………


Recommended